Stewart.] Cretaceous Fishes. 397 



PLATE XLII. 



Figs. 1, 2, 3. — Vertebrae of Xiphactinua audax Leidy (after Hay), one-sixth 

 natural size: ana, basal piece of neural arch; no, neural arch; een, centra. 



Fig. 1. — Palato-quadrate arch of Xiphactinus audax Leidy, one-third natural 

 size: pal, palatine: mpg, mesopterygoid : intj>(/, metapterygoid ; ])t, ptery- 

 goid: 7, quadrate: si/m, symplectic. 



Fig. 5. — Hyomandibular of Xiphactinua audax Leidy, one-third natural size. 



Fig. 6. — Pelvic actinosts of Xiphactinus audax Leidy, one-third natural size. 



Fig. 7. — Ceratohyal of Xiphactinus audax Leidy, one-third natural size. 



PLATE XLIII. 

 Opercular bones of Xiphactinus audax Leidy, one-third natural size. 

 Fig. 1. — Operculum. 

 Fig. 2. — Preopercular. 

 Fig. 3. — Supposed suboperculum. 



PLATE XLIV. 



Cranial bones of Xiphactinus audax Leidy, one-half natural size. 

 Figs. 1, 2, 3, 5. — Bones of uncertain position. 

 Fig. 4. — Probably a fragmentary coracoid. 



PLATES XLV-.4 AND XLV-5. 



Shoulder-girdle of Xiphactinus audax Leidy, one-fourth natural size. 

 Fig. 1. — External view: clc, cleithrum; sc, scapula. 

 Fig. 2. — Internal view of upper end of cleithrum and precoracoid, pcor. 

 Figs. 3,4. — Xiphactinus brachygnathus Stewart: pmx, premaxilla: max, 

 maxilla: den, dentary; dar, dermarticular — one-third natural size. 



PLATE XLVI. 



Bones of Xiphactinus audax Leidy. 



Figs. 1, 2, 3, 4, 5. — Fin-spines and rays, one fourth natural size. 

 Figs. 6, 7. — Hypural bones, one-half natural size. 

 Figs. 8, 9, 10. — Basiosts from pectoral fin, one-half natural size. 

 Figs. 11, 12. — External and internal view of neural arch from near the skull, 

 one-half natural size. 



